Important notes:

• The UI is not made in Jetpack Compose.
• It is extremely important to point out that the development of a layout with an advanced visual aspect was not taken into account.
• The division of modules did not take into account the scalability factor. In a real project, we could create, for example, a multi repository app, where we could have, for example:
  • A data repository, following the "single source of truth (SSOT)" model: https://en.wikipedia.org/wiki/Single_source_of_truth
  • A separate repository for each feature of the project - for example, the urlshortener module. Such feature modules would, in the end, be incorporated into a parent application via maven/gradle, applying a dependency management strategy - BOM or Bill Of Materials (example at, https://firebase.blog/posts/2020/11/dependency -management-ios-android).
  • A repository for managing SDK infrastructure like firebase.
  • A repository for managing skds for analytics...

What is this application?

Urlshortener is a small Android app that allows you to shorten urls and display a history of recently shortened links to your favorite websites.

This app consists of only one screen, which has:

• A text entry where the user can type the URL of the site to shorten;
• A button that will trigger the action of sending this link to the service;
• A list with the recently shortened links/aliases.

Technologies/Architecture/Principles:

• Platform - Android: https://developer.android.com/
• Language - Kotlin: https://kotlinlang.org/
• Single activity - Presentation by Ian Lake -> 'Single activity - Why, when, and how (Android Dev Summit '18)': https://www.youtube.com/watch?v=2k8x8V77CrU&ab_channel=AndroidDevelopers
• Multi-Module - Presentation by Yigit Boyar, Florina Mutenescu -> 'Build a modular Android app architecture (Google I/O'19)': https://www.youtube.com/watch?v=PZBg5DIzNww&ab_channel=AndroidDevelopers
• Navigation component: https://developer.android.com/guide/navigation/navigation-getting-started
• Koin -DI framework: https://insert-koin.io/
• MVVM: https://developer.android.com/topic/architecture
• Clean architecture: https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
• Clean code: https://www.oreilly.com/library/view/clean-code-a/9780136083238/
• Coroutines: https://kotlinlang.org/docs/coroutines-guide.html
• Retrofit: https://square.github.io/retrofit/
• S.O.L.I.D: https://en.wikipedia.org/wiki/SOLID

Tests:

• Unit tests - MockK: https://github.com/mockk/mockk
• Component testing with - Robolectric: http://robolectric.org/
• Instrumented tests with - Espresso: https://developer.android.com/training/testing/espresso

Code organization

The application is divided into 03 modules:

• app: responsible for running the UI tests (in an eventual deploy, this module - and all the code contained in it - will not will be deployed to production).

• core:

  • Infrastructure for communication with the API (ApiClientBuilder, RequestManager), exceptions for communication with the server, etc...
  • Fragment state management: BaseViewModel, ViewState.

• urlshortener: module responsible for implementing the feature. Contains the canvas (UrlShortenerListFragment) with which the user interacts.